The present invention relates to a shoe press jacket with minimal surface abrasion and dimensional change.
A general shoe press is composed, as shown in FIG. 4, of a top roll 12, a top felt 13, a wet web 14, a bottom felt 13', a jacket 11 and a shoe 15 so that the top felt 13, the wet web 14, the bottom felt 13' and the jacket 11 are rotated together with the top roll 12 as the driving source.
As shown in FIG. 3, the jacket 11 is composed of a fabric 1' coated with a resin 6'. In most conventional jackets 11, in order to prevent abrasion due to friction between the jacket 11 and the shoe 15, only the side 11a of the fabric 1' in contact with the shoe is coated with resin, and the surface side 11b' is exposed.
However, the jacket 11 has a short life because the surface side 11b' wears due to slippage between the jacket 11 and the back of the bottom felt 13' as the jacket 11 rotates in contact with the back of the bottom felt 13'. The jacket 11 also frays due to abrasion.
As a countermeasure against the wear and abrasion of the jacket 11 on the surface side 11b', a jacket 11 of a type in which the surface side 11a is also coated with resin has also been developed. Examples of this type jacket are shown in Japanese Patent Publication Nos. 57236/1991 and 15398/1988.
However, the jackets of Japanese Patent Publication Nos. 57236/1991 and 15398/1988 tend to have large deformations in the MD (machine direct) and CD (cross machine direct) directions. This is partly because the fixing force of the base fabric layer due to the resin is inferior owing to the thin resin layer on the surface side, and partly because the resin on the surface side is cracked because of dimensional change in the base fabric layer and the surface abrasion causes moisture from the surface side to percolate through the interior causing swelling.
If this type jacket is used in a closed type shoe press, a situation develops that compels the machine to be stopped during use for repairs such as width trimming or replacing the jacket.